Most FTP clients, including SmartFTP, Cute FTP, WinSCP, Filezilla and many others should only require four things:
The hostname/server/domain you wish to connect to (usually either your domain name or the IP of the server)
Target directory (optional, if you want to open up your website's public directory, use "public_html/" -- that's where all content that is visible to public is)
This information (except target directory) is provided in your welcome email. Simply enter it into your FTP client and it will connect. The main FTP username is equal to your cPanel username, and the same goes for the password.
If you are having difficulties connecting or uploading files, double-check that you have Passive (PASV) Mode enabled in your client. This mode is required to connect to our servers, although a number of FTP clients do not have it enabled by default.